When we're not in the mood for something warm-hearted or uplifting, Martin Amis can usually be counted on to cast a jaundiced eye on everything unlovely about social behavior and human beings in general. But his new novel, despite tour-de-force set pieces and dazzling sentences, is somewhat lackluster.

Although there is mention of a couple of pregnant widows, one of them the protagonist's mother, the title is a rather clunky metaphor for an interregnum of sorts, the morphing of the age of love and responsibility into the hedonistic sexual free-for-all of the '70s.

Most of the novel takes place in 1970, an early summer of love, when a group of young English people gathers in an Italian castle. They eat, swim, sightsee, but mostly they negotiate their way through changing sexual mores, as girls start acting aggressively like boys, and the boys flounder to keep their bearings. The sexual revolution, seen through Amis' eyes, is more a confused and awkward groping in the dark.

At the center stands, or rather fumbles, 20-year-old Keith Nearing, student of literature, lover of Lily, desirer of the elusive Scheherezade and conquest of the unnervingly confident seductress with the telling name, Gloria Beautyman. Keith, when not thinking about sex or having sex, is reading his way through 18th- and 19th-century British fiction, in which sex is a dangerous force, to be avoided until marriage, certainly for women. But in life, the rules have changed. Not only will there routinely be sex before marriage, but sex is increasingly divorced from feeling. Keith struggles with feeling "retrograde ... counter-revolutionary. Under the old regime, love preceded sex; it wasn't that way round anymore." And poor Keith is struggling to write about antinomianism in D.H. Lawrence, which means "doing whatever ... you want all the hours there are."

The text not infrequently brings up the story of Narcissus. It's an unnecessary allusion, since readers will recognize early on that the characters are all vapid narcissists. Amis doesn't have any pungent things to say about the so-called sexual revolution, so the fact that his young people are so boring makes the novel somewhat of a slog. As the author has the narrator, a jaded third-person observer of the goings-on, say: "Sex is bad enough, as a subject, and the self is pretty glutinous too."

Flash-forwards to the late '70s and, eventually, the present strongly suggest the revolution was a bust. Keith is on his third marriage, his promiscuous younger sister dies, and some of the players, like Lily, have settled into the conventional marriage-with-kids and dinner parties. The big changes were a matter of surface, not substance.

Still, there are those local pleasures I spoke of. I'll leave you with one. "He sat on under a sky now crazed with stars -- stars in such wild profusion that the night had no idea what to do with them all. ... Actually of course it did. ... The night is more intelligent than we are -- many Einsteins more intelligent. And so he sat on, under the intelligence of the night."

Brigitte Frase is a writer and book reviewer in Minneapolis.